As microporous materials, zeolites entrap molecules allowing their diffusion, adsorption and reaction
within the channel system. This confinement affects the physico-chemistry of such incoming molecules
in different ways. Derouane pioneered research onto the confinement effect in zeolites and extracted
ideas and conclusions regarding physisorption, catalytic cracking and diffusion. His work on this topic is
reviewed in this article and further updates on the confinement effects by other groups are also analysed.